The present invention relates to a laser diode having an integrated heat sink wherein the heat sink is a body of material having good thermal conductivity which is applied to a semiconductor body close to a laser-active zone and close to resonator mirrors thereof.
It is known to manufacture laser diodes as single components which respectively comprise a heat sink of material having good thermal conductivity, usually metal. In particular, strip laser diodes and "buried layer" laser diodes have a semiconductor body which preferably comprises a plurality of epitaxy layers, particularly a hetero-layer structure. Such a multi-layer structure is manufactured by epitaxial deposition on a substrate member. The actual laser-active zone is situated in a layer which lies close to a surface of the hetero-layer structure and opposite the substrate. In a laser diode having such a structure, the heat necessarily arising in the generation of the laser radiation is consequently generated close to this surface of the layer structure facing away from the substrate. It is therefore meaningful to apply the heat sink on this surface of the layer structure. This is referred to as "upside-down" technology. It is necessary in this technology to apply the heat sink as exactly as possible on the laser diode element, namely such that at least in the region of the one resonator mirror of the laser-active zone, namely in the region of that mirror through which the useful laser beam emerges from the laser diode, the heat sink extends at most up to the level of the mirror but, even better, is set back a few .mu.m. It is thus guaranteed that the useful laser beam emerging divergently from the laser diode does not strike against an edge of the heat sink.